The guy who manage to get a full game file version with transparent background is truly my hero.

Looking at this full-size version (assuming it's really the one in the game), it looks a little weird, like it was drawn over the original. It's especially noticeable in the area around her hair and scarf, it looks like there's a layer below it and an extra line was traced over it. Other CGs like Vanguard's don't seem to have the same issue.